1. Field of the Invention
The present invention relates to a remote reproduction system and a remote reproduction method in which communication is made between a transmitting apparatus and a mobile receiving apparatus which are connected to each other mainly through a mobile wireless network, in which information is transmitted from the transmitting apparatus to the mobile receiving apparatus, and in which the information can be reproduced in the mobile receiving apparatus, as well as a computer program product to realize the system and the method.
2. Description of the Related Art
Nowadays, information communication through the Internet is generalized, and AV (Audio Visual) equipment and a network appliance which have a function of accessing the Internet to make the information communication are used at home. For example, as the AV equipment, an information recording/reproducing apparatus for video and music, such as a DVD recorder, is spread. On the other hand, a mobile terminal, such as a mobile phone, a PDA (Personal Digital Assistance), a car navigation apparatus, and a mobile personal computer, is also spread. Moreover, such a technology is also being spread that the information communication is made between the AV equipment and the mobile terminal through a mobile wireless network, such as a mobile phone network, an IMT (International Mobile Telecommunication)-2000, a PHS (Personal Handyphone System), a wireless LAN (Local Area Network), and a wireless network through the Internet.
By the way, if a user can listen to many songs and many pieces of music or watch a few or several or more movies outside, that is useful. One method to realize this is to provide a mobile information reproducing apparatus, such as a MP3 player and a multimedia player, with a storage device with a large storage capacity. Namely, the storage device which has a storage capacity large enough to store the content data of many songs or movies is incorporated into the mobile information reproducing apparatus. The user stores the content data of many songs or movies into the mobile information reproducing apparatus at home before going out. Then, the user goes out with the mobile information reproducing apparatus, and operates the mobile information reproducing apparatus outside to reproduce the songs or movies. Recently, the mobile information reproducing apparatus provided with a hard disk with a storage capacity of several tens megabytes to several tens gigabytes has been popular.
On the other hand, another method for the user to listen to many songs or watch a few or several or more movies outside is to make wireless communication between the mobile terminal of a portable type and the AV equipment. Namely, an information reproduction function is incorporated into the mobile terminal of a portable type. Then, the information communication is made between the mobile terminal and the AV equipment located at home through the mobile wireless network, to thereby operate the AV equipment by using the mobile terminal and transfer the content data of songs or movies from the AV equipment to the mobile terminal. Then, the content data is reproduced on the mobile terminal. If the size of content data to be reproduced is large, such as movies, streaming reproduction is performed on the mobile terminal. Namely, while the content data is transferred from the AV equipment to the mobile terminal, the content data is reproduced in real time, simultaneously.
Hereinafter, the technology of making the wireless communication between the transmitting apparatus, such as the AV equipment, and the mobile receiving apparatus, such as the mobile terminal; of transferring the content data and/or other information, such as songs, music, movies and texts, from the transmitting apparatus to the mobile receiving apparatus; and of reproducing the data and/or information on the mobile receiving apparatus is referred to as “remote reproduction” or “remote playback.”
According to the remote reproduction technology, the content data of songs or movies can be reproduced while wirelessly transferred from the AV equipment to the mobile terminal, so that it is unnecessary to provide the mobile terminal with a storage device which is large, heavy, and nondurable, such as a hard disk. Thus, it is possible to easily provide a mobile terminal which is small, light, and excellent in portability and durability. Therefore, the user can easily listen to music or watch movies outside. Moreover, according to the remote reproduction technology, the user can freely listen to music or watch movies. For example, the user can watch a movie at home with the AV equipment, stop watching in the middle, and later can watch the rest of the movie by using the mobile terminal outside. This kind of thing can be realized, easily.
By the way, the remote reproduction is expected to be performed while the mobile terminal is in motion. Namely, it is expected that the user reproduces the music or movie with the mobile terminal, while traveling by car, train or bicycle.
As the mobile terminal moves, geography around the mobile terminal changes momentarily. Along with this change, the communication condition between the mobile terminal and the AV equipment changes momentarily. For example, it is assumed that a car the user drives travels on an open road with good visibility at one moment; however, it enters a tunnel at a next moment. As a result, the communication environment around the mobile terminal suddenly becomes bad, and the communication condition between the mobile terminal and the AV equipment suddenly becomes bad. This causes bad communication between the mobile terminal and the AV equipment, makes the reproduction of the content data unstable, and in some cases, this distorts audio or video images. This is undesirable.
Moreover, if the streaming reproduction is performed, another problem may occur due to the deteriorating communication condition. For example, if the content data of movies transmitted from the AV equipment cannot be received on the mobile terminal for a long time due to the deteriorating communication condition, the mobile terminal loses a way to obtain the content data which is transmitted in the not-communicable period while maintaining the present streaming reproduction. In this case, a part of the content data cannot be reproduced, and the contents of the movie are lost partially. As a result, the user needs to watch the movie with the discontinuous content. This is undesirable.